kater->later

Change-Id: If9eaf54c2d706144e2b7c34a3004ad9604dd420f
Resolves: fdo#86931 wrong offsets used to set language

after Chinese conversion. the _aOldSel is the one
that has the start and end index set to the end of the
replacement text and so the calculation only makes
sense on that selection

Change-Id: I152067550d7741579bfc6ca026072b16ac7c2dd6